The sustained good health of any population depends on reliable access to basic resources, such as food, water, shelter and energy. Climate is one of the main factors that influence these foundations.
Throughout the 21st century, there are many evidences that climate change has aggravated human health problems and led to increase in ill-health in many regions and especially in developing countries with low income. Human health impacts related to climate change are greater likelihood of injury and death owing to more intense heat waves and fires, increased risks frim foodborne and waterborne diseases and loss of work capacity and reduced labor productivity in vulnerable populations.
The first detectable changes in human health may well be alterations in the geographic range (latitude and altitude) and seasonality of certain infectious diseases – including vector-borne infections such as malaria and dengue fever, and food-borne infections (e.g. salmonellosis) which peak in the warmer months .
Change in world climate would influence the functioning of many ecosystems and their member species. Likewise, there would be impacts on human health. Some of these health impacts would be beneficial. For example, milder winters would reduce the seasonal winter-time peak in deaths that occurs in temperate countries, while in currently hot regions a further increase in temperatures might reduce the viability of disease-transmitting mosquito populations. Overall, however, scientists consider that most of the health impacts of climate change would be adverse.
Climatic changes over recent decades have probably already affected some health outcomes. Indeed, the World Health Organisation estimated, in its “World Health Report 2002”, that climate change was estimated to be responsible in 2000 for approximately 2.4% of worldwide diarrhoea, and 6% of malaria in some middle-income countries. However, small changes, against a noisy background of ongoing changes in other causal factors, are hard to identify. Once spotted, causal attribution is strengthened if there are similar observations in different population settings.
In Thailand, rise in temperature induces many health-related risks, particularly, heat stress, injuries, and water-borne diseases. Heat stress will lead to greater incidences of heat cramps, exhaustion, and sunstroke, especially in industrial and agricultural sites. A greater amount of stagnant water could increase the number of dengue cases. Nearly ten years ago , rose in temperatures caused to the increase in dengue, heat stress and waterborne disease. Merely nearly 190,000 Thais had to be treated for water-related illnesses and injuries. Dramatic increase in rain season impacts landslide-associated casualties (Marks, 2011).